Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Lots of spray coming from around the engine

Posted by dirk109 on 07/15/07 - 5:02 AM
#1

Hello,

I just bought my DREAM BOAT!! It is a 1969 13' w/ 1980 40 Merc Short Shaft on it. My question is, It seems to throw alot of water around the motor. Big roster tail, Even water in the rear well. The guy I bought it from had put these FINS on the motor to make it plain off quicker, Could this be it? Any info would be great.
Thanks
Sean

Edited by Jeff on 07/15/07 - 10:39 AM

Posted by Derwd24 on 07/15/07 - 6:07 AM
#2

Congratulations, the 13's are great little boats. First thing I'd check is the height/shaft length of the engine. That horizontal part of the motor that the fins are bolted on to should be just even with the bottom of the boat. If it's any lower, you'll get a lot of spray (and also unnecessary drag).

Posted by Jeff on 07/15/07 - 7:39 AM
#3

I agree that the motor sounds like it is mount WAY to low. I am betting the previous owner mounted a 20" motor on the 15" transom without any means to raise the motor to the proper height. Sean could you post some images.

Also here is an example of a old 13' hull with a 20" motor mounted to it. Notice the spacer created to raise the motor up.
link

Edited by Jeff on 07/15/07 - 7:40 AM

Posted by dirk109 on 07/15/07 - 7:56 AM
#4

Here ya go.

Edited by dirk109 on 07/15/07 - 7:58 AM

Posted by Jeff on 07/15/07 - 8:02 AM
#5

Oh ya that motor is way to low.

Posted by joninnj on 07/15/07 - 8:43 AM
#6

The cavitation plate should even with the lowest part of the tansom, or close as possible. from the picture it does seem very low but hard to tell. This may be a long shaft engine, does not seem like a short shaft... You may want to consider a setback/jack plate to compensate. Any pictures from directly behind??

Good luck

Posted by danedg on 07/15/07 - 8:55 AM
#7

Yeah Dirk,
See if you can get a pic from behind...take a straight stick or something and line it up with the hull bottom and see where it ends up in relation to the motor...it should be even with the cav plate. My Suzuki is in the right spot...and puts up a lot more spray than the other motors that have been on the boat...not sure why....
enjoy

Posted by dirk109 on 07/15/07 - 12:29 PM
#8

Where can you find a 40 horse Short Shaft?

Posted by Jeff on 07/15/07 - 12:57 PM
#9

I doubt you will find a 40hp motor with a 15" shaft any more. You are best off getting a a simple jack plate. Like this 5" extension from CMC.

[img]http://cook-mfg.net/cart/bmz_cache/9/95293c748c921c48d5bff2f08b884f39.image.157x200.jpg[/img]

Or this CMCadjustable setback.

[img]http://cook-mfg.net/cart/bmz_cache/e/e1347695694a7550448e9d11968c6e2b.image.250x187.jpg[/img]



Or fabricating one of your own like the one below. Though the quality is not to my standards at least you get the idea.

Edited by Jeff on 07/15/07 - 1:03 PM

Posted by Jeff on 07/15/07 - 12:58 PM
#10

Here is how you want the cavatation plate to line up with the hull.

Posted by Jeff on 07/15/07 - 12:59 PM
#11

2

Posted by Jeff on 07/15/07 - 12:59 PM
#12

3

Posted by dirk109 on 07/15/07 - 2:46 PM
#13

Guys, Thanks for all the info. I will get back to you on whats going on.

Posted by moose on 07/16/07 - 6:54 AM
#14

Sean,
I have a 1970 Merc 40 with a short shaft that is sitting in the garage waiting for someone to need parts. I don't know if the lower ends are interchangeable or not. I do know that Nissan/Tohatsu still makes a short shaft 40 hp two stroke.
Mike